A crop sprayer is used to distribute chemicals, such as herbicides, pesticides, and fertilizers, over crops in a field during a spraying operation. The chemicals are held in a storage tank prior to being sprayed upon the field.
In order to reduce bulk and weight of the chemicals, the chemicals are shipped from the manufacturer as concentrated chemicals. The concentrated chemicals must be diluted with water prior to being sprayed upon the field. To dilute the concentrated chemicals, the concentrated chemicals are loaded into the storage tank that has been partially filled with water.
One manner of loading the concentrated chemicals into the storage tank is for the operator of the crop sprayer to climb on the crop sprayer and pour the concentrated chemicals into an opening defined in the top of the storage tank thereby disadvantageously inconveniencing the operator.
One alternative to the above loading approach is use a venturi system which draws or otherwise sucks the concentrated chemicals from a loading receptacle to the storage tank. The venturi system functions by advancing a quantity of water from an auxiliary water tank through venturi tubing so as to generate a partial vacuum which is used to draw the concentrated chemicals from the loading receptacle into the storage tank. One crop sprayer which utilizes such a venturi system is available from AgChem Equipment Co., Inc. of Minnetonka, Minn. as model no. 544. This particular crop sprayer is sold under the trademark "Rogator".
One disadvantage of using the above venturi-type loading system is that a high velocity flow of water must be generated in order to create a partial vacuum of sufficient magnitude which is capable of drawing the concentrated chemicals from their respective chemical receptacle. This high velocity flow of water in the venturi system has been known on occasion to accidentally become partially diverted during a chemical loading process whereby a violent backflow of concentrated chemicals is forced out of a drain of the chemical receptacle. Such a backflow situation is dangerous since the concentrated chemical may be sprayed upwardly out of the chemical receptacle and come into contact with the crop sprayer operator or other bystanders. In addition, if the concentrated chemicals are sprayed upwardly out of the chemical receptacle, the environment at the loading site may be exposed to these chemicals at a potentially harmful concentration level.
Another disadvantage of using the above venturi-type loading system is that the high velocity flow of water which is present in the system is generated by a hydraulically powered water source. Such a hydraulically powered water source requires a flow of pressurized hydraulic fluid to be supplied thereto in order to enable its operation. This flow of pressurized hydraulic fluid is supplied to the water source by a high capacity hydraulic fluid source. This high capacity hydraulic fluid source is a common hydraulic fluid source of the crop sprayer which supplies pressurized hydraulic fluid to the various subsystems of the crop sprayer such as a hydraulic boom arm manipulation system. In order to generate the required hydraulic pressure within this high capacity hydraulic fluid source, the high capacity hydraulic fluid source is generally coupled to a crankshaft of an internal combustion engine which is carried on or otherwise supported by the crop sprayer. In order to rotate the crankshaft of the internal combustion engine so as to create the required hydraulic pressure within the high capacity hydraulic fluid source, the internal combustion engine must be operating or otherwise in a running mode. Operating the engine during a chemical loading operation consumes fuel and creates a noisy environment which may be unpleasant for the crop sprayer operator or other bystanders. Furthermore, operation of the internal combustion engine may require that the crop sprayer operator use controls remote from the chemical receptacle which may be inconvenient for the crop sprayer operator. In particular, the operator may be required to operate a number of controls located in a cab of the crop sprayer in order to facilitate operation of the crop sprayer's engine thereby causing the operator to make a number of trips between the cab and the chemical receptacle.
Still another disadvantage of using the above venturi-type loading system is that such a loading system is relatively complicated and expensive.
What is needed therefore is an apparatus and method for loading the concentrated chemicals into the storage tank of a crop sprayer which overcomes one or more of the above-mentioned disadvantages.